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我们所在采用不经酰氯化反应的方法合成去草酮的工艺中,需用大量的多聚磷酸(以下简称 PPA)作催化剂和溶剂。工业生产必需将回收的磷酸水溶液脱水再生循环使用,于是,PPA 含量的测定工作必不可少。磷酸溶液可用标准碱滴定,根据所用的指示剂,可中和此酸的三分之一或三分之二,因为叔碱基盐会完全水解,所以,第三个氢在一般情况下不能滴定。磷以磷酸盐形式的重量分析则操作甚为烦琐而又费时。本文是采用磷酸按镁沉
Where we are not using the method of acyl chloride synthesis of deoxalone process, the need for a large number of polyphosphoric acid (hereinafter referred to as PPA) as a catalyst and solvent. Industrial production of recycled phosphoric acid solution must be recycled dehydration cycle, so, PPA determination of the content necessary. The phosphoric acid solution can be titrated with standard base and depending on the indicator used one third or two thirds of this acid can be neutralized since the tertiary base salt is completely hydrolyzed so that the third hydrogen can not be titrated under normal conditions . Gravimetric analysis of phosphorus in the form of phosphate is very cumbersome and time consuming. This article is the use of phosphate by magnesium sink